Spectrum Visible and near infrared reflectance spectrum of amorphous silica from crater wall(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate-rich coatings (alunite) from an altered crater wall(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate-rich coatings (jarosite) from an altered crater wall(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate (jarosite, alunite) and hematite-bearing coatings from an altered crater wall(Solfatara Crater, Italy)

Spectrum Visible and near infrared reflectance spectrum of amorphous silica from mud pots(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of amorphous silica from mud pots(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of amorphous silica from a dry mud pot(Solfatara Crater, Italy)

Spectrum Visible and near infrared reflectance spectrum of sulfur needles from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen, alum-K) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen, alum-K, Goldichite) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunite,alunogen, alum-K) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen, alum-K) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen, alum-K, alunite) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alunogen, Goldichite) from within a fumarolic vent(Solfatara Crater, Italy) Spectrum Visible and near infrared reflectance spectrum of sulfate deposits (alum-K, alunogen, alunite) from within a fumarolic vent(Solfatara Crater, Italy)